1. Technical Field
Example embodiments relate generally to non-volatile memory devices and more particularly to non-volatile memory devices with enhanced program accuracy and a method of programming non-volatile memory devices more accurately.
2. Discussion of the Related Art
Semiconductor memory devices are classified into volatile memory devices and non-volatile memory devices. The volatile memory device loses stored data when supply voltage is not delivered. The non-volatile memory device keeps stored data when supply voltage is not delivered. The non-volatile memory device includes a flash memory device which may erase data and program data electrically.
Operations of the non-volatile memory device are classified into a program mode, a read modem, and an erase mode. A user may write data to memory cells included in the non-volatile memory device in the program mode. A user may read data from the memory cells in the read mode. A user may erase the stored data of the memory cells in the erase mode.
In general, the non-volatile memory device stores data to the memory cells by changing a threshold voltage of the memory cells. A memory cell included in the non-volatile memory device may have a first threshold voltage distribution representing an erased status or a second threshold voltage distribution representing a programmed status. Therefore, the non-volatile memory device may read stored data of the memory cell based on threshold voltage distribution of the memory cells.
As size of the memory cell array included in the non-volatile memory device increase, a difference between a threshold voltage of a first memory cell, which is closer to an address decoder, and a threshold voltage of a second memory cell, which is farther from the address decoder, increases during program operation.